Testing of 30-GHz low noise receivers

NASA-sponsored studies of the growth in communications traffic have indicated that the frequency spectrum allocated to fix-service satellites at the C and Ku bands will reach saturation by the early 1990's. The next higher frequency bands allocated for communications satellites are 27.5 to 30 GHz for the uplink and 17.7 to 20.2 GHz for the downlink. Current plans for developing satellite systems that use these bands include a NASA demonstration satellite (ACTS). One of the components identified as critical to the success of that mission is a 27.5 to 30 GHz satellite receiver. In response to that identification, NASA has sponsored the development of such a receiver to the proof-of-concept (POC) level. Design and fabrication of such POC model receivers was carried out under parallel contracts awarded to LNR Communications, Inc. of Hauppauge, New York and to ITT Defense Communications Division of Nutley, New Jersey. The most significant of the performance goals were a 5 dB maximum noise figure, a 2.5 GHz passband, and 20 dB RF to IF gain. Following delivery of hardware from each of the contractors, an in-house test program was undertaken at NASA's Lewis Research Center in order to verify the contractor-reported performance and to provide a comparison of the two receivers under identical test conditions. The present paper reports the results of those tests.